In an air-conditioning system installed in a large construction such as an office building, multiple indoor units provided respectively on the floors or in the floor divisions are connected to an outdoor unit provided on the rooftop via refrigerant pipes. Thus, a heat pump conducting heat exchange between the indoor air and outdoor air is constructed.
In a multi-room air-conditioning system of the above kind, multiple indoor units are connected to a single outdoor unit in parallel. Therefore, the capacity (capability) of the outdoor unit is determined based on the total of the capacities (the total capacity) of the indoor units connected to the outdoor unit.
However, if the capacity of the outdoor unit is smaller than the total capacity of the indoor units, it is sometimes difficult to supply the refrigerant to the indoor units at flow rates requested by the indoor units. In such a case, for example, it is necessary to give priority in supply of the refrigerant to the indoor unit requesting the largest quantity of refrigerant and divide the remaining refrigerant among the remaining indoor units (for example, see Patent Literature 1).